The Stovebolt Site Forums The Shop Area Engine Shop 235 to 235 swap

I have read many postings and tech tips regarding swapping out a 216 in favor of a 235. When I bought my '49 half-ton it came with a '51 splash oiled 235. I have since purchased a used '55 full pressure oiled 235 to replace it. I understand the necessity of reusing the bellhousing (probably from a 216) that came installed in the truck. However, I wondered if I could use the flywheel, clutch assembly and starter from the newer engine. It uses a larger clutch (10" instead of the 9 1/8")and different flywheel (168 teeth?). As an experiment, since I have the engine out, I installed the old bellhousing with the newer flywheel and starter to see if it would work together. After testing for about an hour, it seemed to work fine. I would like use this setup because of the larger clutch surface.

Has anyone tried this before or am I missing something? The only change I think I will need to make is using the shorter throwout bearing.

You can do this, but the newer starter needs 12 volts. That's the only issue. I did this with my 261, except I had the new flywheel machined to accept the old 6v ring gear so I could use the old starter. It cost me $50 and works great.

Here's the important part; swap the motor but keep ALL the parts including bellhousing, starter, flywheel, clutch etc etc from the old 216. When you try to mix up these pieces is when you get in trouble. The 6 volt starter loves the 12 volts.
My 46 is a 261, the bellhousing is original as are all the pieces inside, no problems.

BTW, Im using a 1946 11' flywheel, disc and pressure plate from a 2 ton truck. I've seen guys try to stuff a 11"er from a later 50s truck and it would not go into the OLD bellhousing.

Another point on the old trucks; the bellhousing that fits your truck is the key piece. It is the point of attachment for the main mounts, the trans, the master cylinder and pedal mount (on some years). Whatever inline motor you use 216,235 or 261 or even GMC will work forward of the bellhousing. BUT, everything back of the bellhousing may not necessarily interchange without some mods.

Thanks 4ontheFloor. Since I'm also converting to 12 volts, the starter won't be an issue. Did you end up using the shorter throwout bearing, 1 7/8" vs. 1 1/4"?

Yes, I think I did. I stuffed an 11" HD clutch into the 216 bellhousing. The 261 was out of a '62 suburban with a hydraulic clutch but the pressure plate and clutch fit in the 216 bellhousing just fine with a little parts swapping. It was a tight fit and I had to pick through my parts bin to find a shorter bearing, but it all went in just fine. I don't remember the dimension but it was shorter than the one from the 216. In fact, I think I might have used a different clutch fork, maybe one from a '57 235, but I'm not sure.

Go with the biggest clutch you can get ahold of, 235's may not have much horsepower but they do put out gobs of torque.